The media is made up of ignorant people who know nothing about a subject, but like to spout off sensationalist bull hockey that will sell news papers or boast ratings of news TV shows. They will grasp onto whatever becomes an icon of that of which they like to spout.
Unfortunately, they use images of Buck knives because of a long standing use of Buck knives by some pretty iconic images of violence. The biker gangs and Charles Mansons deadly groupies. In 1963 when Buck came out with the 110, they revolutionized the knife industry. They also revolutionized the knife carrying habits of some criminal elements as a by product. By the close of the 1960's, the iconic Buck 110 was being advertised in magazines like Iron Horse, Chopper, and other motorcycles mags as the "Official Biker Knife". That was real good for public relations of Buck! Every swinging richard with a leather vest and Harley had a Buck 110 on his hip, and if he didn't, then he had a Buck 119 there. Those two knives were used in a very high degree of crimes. If the switchblade was the James Dean rebel choice of the 1950's, they Buck knife was the choice of the 60's and carried well over into most of the 70's. It didn't help that Manson's killers all used Buck's in their crimes, and those Bucks were exhibits in the trial. News reporters being news reporters, they pictured the Buck knife in the list of exhibits. With some elements of the society, this was only an enforcement of how "bad ass" the Buck knife was and they all had to have one.
When I served in the army and did a tour in Vietnam, every single swinging richard there had a 110 on their belt, and a lot of the troops in the field had a 119 on their web gear. Reporters on the scene doing live reports photographed the soldiers with Buck knives and the image was in every Newsweek, Time, and Life. The hype and BS started to build up with idiots spreading "My Uncle Bob was in 'nam, and killed 54 charlie's with his Buck knife!" kind of crap. By the end of the 70's the Buck knife had become ingrained in peoples minds as THE bad assed knife. The only good thing that happened was the rise of the balisong in Hollywood in the 1980's. And the 'Rambo' knife craze. They took some attention away from the Buck knife.
TV shows and Hollywood had scores of bali wielding bad guys doing eveil with the 'butterfly knife' that soon the lawmakers were on a role just like the anti switchblade laws of the late 1950's. TV and movies have done most damage to knives than any criminals by sensationalizing the tool. Add in the slasher films where the killer psycho is wielding a Buck knife, and the image has been cast in bronze for all time. A highly recognizable item is the ticket. Even use by a good guy, they go for the image. In the TV show Longmire, they have the good guy using a Buck 110, even though in the books, Longmire uses a Case bone handle trapper. Image.
Everytime a gun crime is committed, the media has the image of a Glock or M16 on the screen. It's always been about the image, and always will be. Sometimes the image has had some help by the item being used in a crime. Sometimes when you get to be real popular, all the people using that item ain't saints.